WO2017094474A1

WO2017094474A1 - Adhesive composition, adhesive sheet and optical film with adhesive

Info

Publication number: WO2017094474A1
Application number: PCT/JP2016/083524
Authority: WO
Inventors: 景文鄭; 宰旭鄭; 公平森岡
Original assignee: 住友化学株式会社
Priority date: 2015-12-01
Filing date: 2016-11-11
Publication date: 2017-06-08
Also published as: TW201726873A; TWI729036B; KR20180087293A; JP2017101136A; CN108291126B; CN108291126A; KR102538808B1; JP6721322B2

Abstract

[Problem] To provide a novel adhesive composition which has an adequate adhesive power with respect to glass substrates, while being able to have improved releasability by adding water to the interface between an adhesive layer and a glass substrate upon separation. [Solution] An adhesive composition which contains an acrylic resin, a crosslinking agent and a silane compound represented by formula (I). (In formula (I), R₁ represents an alkyl group having 1-14 carbon atoms, an aralkyl group, an aryl group or an alkenyl group; and R₂ represents an alkyl group having 1-6 carbon atoms.)

Description

Adhesive composition, adhesive sheet and optical film with adhesive

The present invention relates to an adhesive composition suitable for an optical film, an adhesive sheet using the same, and an optical film with an adhesive. The present invention also relates to an optical laminated body in which this optical film with an adhesive is laminated on a glass substrate and is suitably used for liquid crystal display.

A polarizing plate is widely used by being mounted on a liquid crystal display device. A polarizing plate generally has a transparent protective film laminated on both sides of a polarizing film, a pressure-sensitive adhesive layer is formed on the surface of at least one protective film, and a release film is stuck on the pressure-sensitive adhesive layer. is doing.
In addition, a retardation film is laminated on a polarizing plate in which a protective film is bonded to both sides of the polarizing film to form an elliptical polarizing plate, and an adhesive layer / release film is attached in this order to the retardation film side. Sometimes. Furthermore, an adhesive layer / release film may be stuck in this order on the surface of the retardation film. In this specification, the polarizing plate, the elliptically polarizing plate, the retardation film and the like provided with the pressure-sensitive adhesive layer are collectively referred to as an optical film. Such an optical film with an adhesive is laminated on a glass substrate such as a liquid crystal cell to constitute a liquid crystal display device.

The pressure-sensitive adhesive composition for forming a pressure-sensitive adhesive layer applied to an optical film has a single amount of a acrylate ester as a main component and a polar functional group such as a hydroxyl group or a carboxyl group from the viewpoint of transparency and weather resistance. Many (meth) acrylic resins produced by copolymerizing the body are used. A crosslinking agent is blended with such a (meth) acrylic resin to give the required cohesive strength. Moreover, the adhesiveness of an adhesive layer and a glass substrate is improved by mix | blending a silane type compound with such (meth) acrylic resin. As the silane-based compound, for example, 3-glycidoxypropyltrimethoxysilane is widely used (see JP 2013-181086 A).

JP 2013-181086 A

適度 Appropriate adhesive strength is required for the adhesive layer of the optical film with adhesive. An optical film with an adhesive gives, for example, an optical laminate for liquid crystal display by laminating on a glass substrate of a liquid crystal cell. However, by having an appropriate adhesive strength, the optical laminate can be used under high temperature conditions and wet heat. Under conditions and in an environment where heating and cooling are repeated, the pressure-sensitive adhesive layer absorbs and relaxes the stress caused by the dimensional change of the optical film and the glass substrate. Lifting and peeling of the pressure-sensitive adhesive layer are suppressed. That is, the durability is excellent.

The adhesive layer of the optical film with an adhesive is required to have an appropriate adhesive strength as described above. On the other hand, when the optical film with an adhesive is bonded to a liquid crystal cell, the optical film Since the film is once peeled off and then a new film is attached again, it is also required that the peelability at that time is good. If the peelability is low, problems such as the adhesive remaining on the glass substrate occur.

The present invention has a novel pressure-sensitive adhesive composition that has an appropriate adhesive force to the glass substrate and can improve releasability by adding water to the interface between the pressure-sensitive adhesive layer and the glass substrate at the time of peeling, The present invention also provides an adhesive sheet, an optical film with an adhesive, and an optical laminate using the same.

The present invention provides the following pressure-sensitive adhesive composition, pressure-sensitive adhesive sheet, optical film with pressure-sensitive adhesive, and optical laminate.

[1] (Meth) acrylic resin, crosslinking agent, and the following formula (I)

(In the above formula (I), R ₁ represents an alkyl group having 1 to 14 carbon atoms or an aralkyl group, aryl group or alkenyl group; R ₂ represents an alkyl group having 1 to 6 carbon atoms)
A pressure-sensitive adhesive composition containing a silane compound represented by:

[2] The pressure-sensitive adhesive composition according to [1], wherein the silane compound is contained in an amount of 0.03 to 10 parts by weight with respect to 100 parts by weight of the (meth) acrylic resin.

[3] The pressure-sensitive adhesive composition according to [1] or [2], wherein the silane compound is 3-ureidopropyltrialkoxysilane.

[4] The pressure-sensitive adhesive composition according to [1] to [3], wherein the crosslinking agent is an isocyanate crosslinking agent.

[5] A pressure-sensitive adhesive sheet formed into a sheet shape using the pressure-sensitive adhesive composition according to [1] to [4].

[6] The pressure-sensitive adhesive sheet according to [5], which is formed on a plastic film.
[7] The pressure-sensitive adhesive sheet according to [6], wherein the plastic film is a release film subjected to a release treatment.

[8] An optical film with an adhesive comprising an optical film and the adhesive sheet according to [5] to [7] bonded to the optical film.

[9] The optical film with an adhesive according to [8], wherein the optical film is a polarizing plate or a retardation film.

[10] An optical laminate in which the optical film with an adhesive according to [8] or [9] is bonded to a glass substrate on the adhesive sheet side.

According to the present invention, the pressure-sensitive adhesive layer has an appropriate pressure-sensitive adhesive force to the glass substrate, and exhibits excellent releasability by adding water to the interface between the pressure-sensitive adhesive layer and the glass substrate at the time of peeling. Can be provided, and a pressure-sensitive adhesive sheet and an optical film with a pressure-sensitive adhesive using the same can be provided.

It is a cross-sectional schematic diagram which shows the example of the suitable layer structure of the optical laminated body which concerns on this invention.

Hereinafter, the present invention will be described in detail. The pressure-sensitive adhesive composition of the present invention contains a (meth) acrylic resin (A), a crosslinking agent (B), and a silane compound (C) represented by the following formula (I).

In the above formula (I), R ₁ is an alkyl group having 1 to 14 carbon atoms, an aralkyl group, an aryl group or an alkenyl group. R ₂ represents an alkyl group having 1 to 6 carbon atoms. According to the pressure-sensitive adhesive composition of the present invention, by containing the silane compound (C) represented by the above formula (I), it has excellent adhesion to the glass substrate, has moderate pressure-sensitive adhesiveness, and durability. A pressure-sensitive adhesive layer that can form an excellent pressure-sensitive adhesive layer and exhibits excellent releasability by adding water to the interface between the pressure-sensitive adhesive layer and the glass substrate when peeling the pressure-sensitive adhesive layer from the glass substrate Can be formed. First, each component which comprises an adhesive composition is demonstrated.

[(Meth) acrylic resin (A)]
The (meth) acrylic resin (A) constituting the pressure-sensitive adhesive composition of the present invention has a structural unit derived from (meth) acrylic acid ester (A-1) as a main component and a (meth) acrylic single unit having a hydroxyl group. Those containing a structural unit derived from the monomer (A-2) are preferred. Furthermore, those containing a structural unit derived from a carboxyl group-containing (meth) acrylic acid ester (A-3) are preferred.

The above (meth) acrylic acid ester (A-1) is represented by the following formula (II).

In the above formula (II), R ₃ represents a hydrogen atom or a methyl group; R ₄ represents an alkyl group or an aralkyl group having 14 or less carbon atoms, and the hydrogen atom constituting these groups is a group —O— ( C ₂ H ₄ O) _m —R ₅ may be substituted, wherein m represents 0 or an integer of 1 to 4, and R ₅ represents an alkyl group or an aryl group having 12 or less carbon atoms.

The carboxy group-containing (meth) acrylic acid ester (A-3) is represented by the following formula (III).

In the above formula (III), R ₆ represents a hydrogen atom or a methyl group; A represents a divalent organic group having 2 to 4 carbon atoms.

In this specification, (meth) acrylic acid means that either acrylic acid or methacrylic acid may be used. In addition, “(meth)” in the case of (meth) acrylate, (meth) acrylic resin, etc. is the same. This is the purpose. In the present specification, the (meth) acrylic acid ester (A-1) represented by the above formula (I) is simply referred to as “monomer (A-1)” and a (meth) acrylic monomer having a hydroxyl group ( A-2) is simply referred to as “monomer (A-2)”, and the carboxyl group-containing (meth) acrylic acid ester (A-3) represented by the above formula (III) is simply referred to as “monomer (A— 3) ”may be called.

Among the monomers (A-1), those in which R ₄ in the above formula (II) is an unsubstituted alkyl group, specifically, methyl acrylate, ethyl acrylate, propyl acrylate, n-acrylate Linear alkyl acrylates such as butyl, n-octyl acrylate, and lauryl acrylate; branched alkyl acrylates such as isobutyl acrylate, 2-ethylhexyl acrylate, and isooctyl acrylate; Linear alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, n-octyl methacrylate, and lauryl methacrylate; and isobutyl methacrylate, 2-methacrylic acid 2- Minutes such as ethylhexyl and isooctyl methacrylate Examples are branched alkyl methacrylates.

Among these, n-butyl acrylate is preferable. Specifically, among all monomers constituting the (meth) acrylic resin (A), n-butyl acrylate is 50% by weight or more. In addition, it is preferably used so as to satisfy the above-mentioned regulations regarding the monomer (A-1).

Further, among the monomers (A-1), specific examples of R ₄ in the formula (II) being an aralkyl group include benzyl acrylate and benzyl methacrylate.

Next, in the monomer (A-1), the hydrogen atom of the alkyl group or aralkyl group constituting R ₄ in the formula (II) is substituted with the group —O— (C ₂ H ₄ O) _m —R ₅ . I will explain what is being done. In this group —O— (C ₂ H ₄ O) _m —R ₅ , m is 0 or an integer of 1 to 4 as defined above, but 0, 1 or 2 is particularly preferable. R _{5 is} also an alkyl group or aryl group having 12 or less carbon atoms, as defined above, and may be linear or branched as long as the alkyl group has 3 or more carbon atoms. Examples of the aryl group constituting R ₅ include phenyl and naphthyl, as well as nuclear alkyl-substituted phenyl including tolyl, xylyl, ethylphenyl, and biphenylyl (or phenylphenyl). R ₅ is particularly preferably these aryl groups.

In the monomer (A-1), R ₄ in the formula (II) is an alkyl group, and the hydrogen atom is substituted with a group —O— (C ₂ H ₄ O) _m —R _5. Specifically, 2-methoxyethyl acrylate, ethoxymethyl acrylate, 2-phenoxyethyl acrylate, 2- (2-phenoxyethoxy) ethyl acrylate, and 2- (o-phenylphenoxy) ethyl acrylate Such as alkoxyalkyl-, aryloxyalkyl- or aryloxyethoxyalkyl-esters of acrylic acid; 2-methoxyethyl methacrylate, ethoxymethyl methacrylate, 2-phenoxyethyl methacrylate, 2- (2-phenoxyethoxy) methacrylate Alcohols of methacrylic acid such as ethyl and 2- (o-phenylphenoxy) ethyl methacrylate Shiarukiru -, aryloxyalkyl - or aryloxy ethoxyalkyl - such esters are exemplified.

These monomers (A-1) can be used alone or in combination with a plurality of different monomers. As described above, the monomer (A-1) is particularly preferably composed mainly of n-butyl acrylate, but in addition, other (meth) acrylic acid esters corresponding to the formula (II) Copolymerization is also effective. As a suitable composition of the monomer (A-1), among all the monomers constituting the (meth) acrylic resin (A), n-butyl acrylate is 50% by weight or more, Separately, a hydrogen atom represented by the above formula (II) and constituting R ₄ in the formula is a group —O— (C ₂ H ₄ O) _m —R ₅ (where m and R _{5 are} Is as defined above) and is a mixture of 3 to 15% by weight of a (meth) acrylic acid ester substituted with an alkyl group.

Examples of the (meth) acrylic monomer (A-2) having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 4-hydroxy (meth) acrylate. Examples include butyl and 2- (2-hydroxyethoxy) ethyl (meth) acrylate. Of these, 2-hydroxyethyl acrylate is preferably used as one of the monomers (A-2) constituting the (meth) acrylic resin (A).

The carboxyl group-containing (meth) acrylic acid ester (A-3) is represented by the above formula (III). In this formula (III), R ₆ is a hydrogen atom or a methyl group, and A is a divalent organic group having 2 to 4 carbon atoms. The divalent organic group represented by A is typically alkylene, which is also preferably linear alkylene, but the (meth) acrylic acid moiety CH ₂ ═C (R ₆ ) COO— Assuming that the carbon chain connecting the terminal carboxyl group —COOH is at least 2 in series, the chain may be branched as long as it has 3 or more carbon atoms. Among the formulas (III), it is preferable to use an acrylate ester as the monomer (A-3). Examples thereof include 2-carboxyethyl acrylate, 3-carboxypropyl acrylate, 4-carboxy acrylate. Examples include butyl. Of course, compounds obtained by changing these acrylic acid esters to methacrylic acid esters can also be the monomer (A-3).

The above-mentioned 2-carboxyethyl acrylate is usually produced by dimerization of acrylic acid, and in that case, in addition to 2-carboxyethyl acrylate, which is the main component, acrylic acid itself or a trimer of acrylic acid. It is often obtained as a mixture with the above oligomers and sold as such in the state of a mixture. Thus, it goes without saying that other carboxyl group-containing (meth) acrylic monomers may be copolymerized with the monomer (A-3).

In the (meth) acrylic resin (A) defined in the present invention, the content of the structural unit derived from the (meth) acrylic acid ester represented by the above formula (II), that is, the monomer (A-1) is 90 The content of the structural unit derived from the (meth) acrylic monomer having a hydroxyl group, that is, the monomer (A-2) is 0.1 to 6% by weight, and The content of the structural unit derived from the carboxyl group-containing (meth) acrylic acid ester represented by the formula (III), that is, the monomer (A-3) can be 0.01 to 0.4% by weight. . By copolymerizing the monomers (A-1) and (A-2) in such a limited ratio, a pressure-sensitive adhesive composition that gives a pressure-sensitive adhesive sheet with excellent processability can be prepared. Of course, the total amount of structural units derived from each of the monomers (A-1), (A-2) and (A-3) does not exceed 100% by weight.

The (meth) acrylic resin (A) used in the present invention contains structural units derived from monomers other than the monomers (A-1), (A-2) and (A-3) described above. You may go out. Examples of monomers other than monomers (A-1), (A-2) and (A-3) include monomers and molecules other than those of formula (III) having polar functional groups other than hydroxyl groups. (Meth) acrylic acid ester having alicyclic structure, styrene monomer, vinyl monomer, (meth) acrylamide derivative, monomer having multiple (meth) acryloyl groups in the molecule, etc. is there.

A monomer other than the formula (III) having a polar functional group other than a hydroxyl group will be described. The polar functional group other than the hydroxyl group here may be a free carboxyl group, a heterocyclic group including an epoxy ring, or the like. The acrylic acid itself and oligomers of trimer or higher of acrylic acid described above for the monomer (A-3) correspond to monomers other than the formula (III) having a free carboxyl group. Examples of the monomer having a heterocyclic group include acryloylmorpholine, vinylcaprolactam, N-vinyl-2-pyrrolidone, tetrahydrofurfuryl (meth) acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, 3,4-epoxy. Examples include cyclohexylmethyl (meth) acrylate and glycidyl (meth) acrylate.

When copolymerizing a monomer having a polar functional group other than a hydroxyl group, a (meth) acrylic monomer (A-2) having a hydroxyl group and a carboxyl group-containing (meth) acrylic compound represented by the above formula (III) Including the acid ester (A-3), the total amount of monomers having a polar functional group is 8% by weight or less based on the total monomers constituting the (meth) acrylic resin (A). It is preferable to do this.

Next, (meth) acrylic acid ester having an alicyclic structure in the molecule will be described. The alicyclic structure is a cycloparaffin structure having usually 5 or more carbon atoms, preferably about 5 to 7 carbon atoms. Specific examples of the acrylate ester having an alicyclic structure include isobornyl acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, cyclododecyl acrylate, methylcyclohexyl acrylate, trimethylcyclohexyl acrylate, tert-acrylate Examples include butylcyclohexyl, α-ethoxyacrylate cyclohexyl, cyclohexylphenyl acrylate, and the like. Specific examples of the methacrylic acid ester having an alicyclic structure include isobornyl methacrylate, cyclohexyl methacrylate, dicyclopentanyl methacrylate, cyclododecyl methacrylate, methyl cyclohexyl methacrylate, trimethyl cyclohexyl methacrylate, methacrylic acid. Examples include tert-butylcyclohexyl and cyclohexylphenyl methacrylate.

Examples of styrenic monomers include styrene, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, triethyl styrene, propyl styrene, butyl styrene, hexyl styrene, heptyl styrene, and octyl styrene. Alkyl styrenes; halogenated styrenes such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, and iodostyrene; and nitrostyrene, acetylstyrene, methoxystyrene, divinylbenzene, and the like.

Examples of vinyl monomers include: vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, and vinyl fatty acid esters such as vinyl laurate; vinyl halides such as vinyl chloride and vinyl bromide; Vinylidene halides such as vinylidene chloride; nitrogen-containing aromatic vinyls such as vinylpyridine, vinylpyrrolidone, and vinylcarbazole; conjugated diene monomers such as butadiene, isoprene, and chloroprene; and acrylonitrile, methacrylonitrile, etc. .

Examples of (meth) acrylamide derivatives include N-methylol (meth) acrylamide, N- (2-hydroxyethyl) (meth) acrylamide, N- (3-hydroxypropyl) (meth) acrylamide, N- (4- Hydroxybutyl) (meth) acrylamide, N- (5-hydroxypentyl) (meth) acrylamide, N- (6-hydroxyhexyl) (meth) acrylamide, N- (methoxymethyl) (meth) acrylamide, N- (ethoxymethyl) ) (Meth) acrylamide, N- (propoxymethyl) (meth) acrylamide, N- (butoxymethyl) (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N- Isopropyl (meth) acrylamide, N- (3- Methylaminopropyl) (meth) acrylamide, N- (1,1-dimethyl-3-oxobutyl) (meth) acrylamide, N- [2- (2-oxo-1-imidazolidinyl) ethyl] (meth) acrylamide, 2- And acryloylamino-2-methyl-1-propanesulfonic acid.

Examples of monomers having a plurality of (meth) acryloyl groups in the molecule include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and 1,9-nonane. Two diols in the molecule, such as diol di (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and tripropylene glycol di (meth) acrylate Monomers having a meth) acryloyl group; monomers having three (meth) acryloyl groups in the molecule, such as trimethylolpropane tri (meth) acrylate.

A monomer other than the monomers (A-1), (A-2) and (A-3) which are components of the (meth) acrylic resin (A) and having no polar functional group is copolymerized. In this case, the amount is preferably 5% by weight or less based on the total monomers constituting the (meth) acrylic resin (A).

The resin component constituting the pressure-sensitive adhesive composition is the (meth) acrylic acid ester represented by the formula (II) described above, that is, the monomer (A-1), a (meth) acrylic monomer having a hydroxyl group. Resin, ie, monomer (A-2), and carboxyl group-containing (meth) acrylic acid ester represented by formula (III), ie, an acrylic resin having a structural unit derived from monomer (A-3) Two or more types of (A) may be mixed. In addition, (meth) acrylic resin (A) having a predetermined proportion of structural units derived from monomers (A-1), (A-2) and (A-3) is different from (meth) acrylic. A resin may be mixed. Examples of the different (meth) acrylic resin mixed in this case include those having a structural unit derived from the (meth) acrylic acid ester of the above formula (II) and having no polar functional group. The (meth) acrylic resin (A) having structural units derived from the monomers (A-1), (A-2) and (A-3) in a predetermined ratio is composed of the whole (meth) acrylic resin, It is preferably 80% by weight or more, more preferably 90% by weight or more.

As the (meth) acrylic resin (A), it is preferable to employ a resin having a weight average molecular weight Mw in the range of 500,000 to 2,000,000 in terms of standard polystyrene by gel permeation chromatography (GPC). The weight average molecular weight Mw is particularly preferably 500,000 to 1,700,000. When the weight average molecular weight in terms of standard polystyrene is 500,000 or more, the adhesiveness under high temperature and high humidity is improved, and the possibility of occurrence of floating or peeling between the glass substrate and the pressure sensitive adhesive sheet is reduced. And reworkability tends to be improved.
In addition, when the weight average molecular weight is 2 million or less, even if the dimension of the optical film bonded to the pressure-sensitive adhesive sheet changes, the pressure-sensitive adhesive layer fluctuates following the dimensional change, so the liquid crystal cell This is preferable because there is no difference between the brightness of the peripheral edge and the brightness of the central portion, and white spots and color unevenness tend to be suppressed. The molecular weight distribution represented by the ratio Mw / Mn of the weight average molecular weight Mw and the number average molecular weight Mn is not particularly limited, but is preferably in the range of about 3 to 7, for example.

The (meth) acrylic resin (A) preferably has a glass transition temperature in the range of −10 to −60 ° C. in order to exhibit adhesiveness. The glass transition temperature of the resin can be measured by a differential scanning calorimeter.

The (meth) acrylic resin (A) can be produced by various known methods such as a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, and a suspension polymerization method. In the production of this (meth) acrylic resin, a polymerization initiator is usually used. The polymerization initiator is used in an amount of about 0.001 to 5 parts by weight with respect to a total of 100 parts by weight of all monomers used in the production of the (meth) acrylic resin.

As the polymerization initiator, a thermal polymerization initiator, a photopolymerization initiator, or the like is used. Examples of the photopolymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone. Examples of thermal polymerization initiators include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl-2,2'-azobis (2-methylpropio) And azo compounds such as 2,2′-azobis (2-hydroxymethylpropionitrile); lauryl peroxide, tert-butyl hydroperoxide, benzoyl peroxide, tert-butyl peroxybenzoate, cumene hydroper Oxide, diisopropylperoxydicarbonate, dipropylperoxydicarbonate, tert-butylperoxide Organic peroxides such as xineodecanoate, tert-butyl peroxypivalate, and (3,5,5-trimethylhexanoyl) peroxide; inorganic peroxides such as potassium persulfate, ammonium persulfate, and hydrogen peroxide An oxide etc. can be mentioned. A redox initiator using a peroxide and a reducing agent in combination can also be used as the polymerization initiator.

As the method for producing the (meth) acrylic resin, the solution polymerization method is preferable among the methods shown above. A specific example of the solution polymerization method will be described. A desired monomer and an organic solvent are mixed, and a thermal polymerization initiator is added in a nitrogen atmosphere to about 40 to 90 ° C., preferably 50 to 80 ° C. A method of stirring at about 0 ° C. for about 3 to 15 hours can be mentioned. Moreover, in order to control reaction, you may add a monomer and a thermal-polymerization initiator continuously or intermittently during superposition | polymerization, or may be added in the state melt | dissolved in the organic solvent. Examples of the organic solvent include aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; aliphatic alcohols such as propyl alcohol and isopropyl alcohol; acetone, methyl ethyl ketone, and methyl isobutyl. Ketones such as ketones can be used.

[Crosslinking agent (B)]
A crosslinking agent (B) is mix | blended with the above (meth) acrylic resins (A). The crosslinking agent (B) is a compound having at least two functional groups in the molecule that can react with a hydroxyl group or a carboxyl group, which are polar functional groups in the (meth) acrylic resin (A), to crosslink the (meth) acrylic resin. Specifically, an isocyanate compound, an epoxy compound, a metal chelate compound, an aziridine compound and the like are exemplified.

Isocyanate compounds are compounds having at least two isocyanato groups (—NCO) in the molecule, such as tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, Examples thereof include hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, and triphenylmethane triisocyanate. In addition, adducts obtained by reacting these isocyanate compounds with polyols such as glycerol and trimethylolpropane, and those obtained by making the isocyanate compounds into dimers, trimers, and the like can also be used as crosslinking agents for pressure-sensitive adhesives. Two or more isocyanate compounds can be mixed and used.

The epoxy compound is a compound having at least two epoxy groups in the molecule, for example, bisphenol A type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether. 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, N, N-diglycidylaniline, N, N, N ′, N′-tetraglycidyl-m-xylenediamine and the like. Two or more types of epoxy compounds can be mixed and used.

Examples of the metal chelate compound include compounds in which acetylacetone or ethyl acetoacetate is coordinated to a polyvalent metal such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium and zirconium. Can be mentioned.

An aziridine-based compound is a compound having at least two 3-membered ring skeletons composed of one nitrogen atom and two carbon atoms, also called ethyleneimine, for example, diphenylmethane-4,4′-bis ( 1-aziridinecarboxamide), toluene-2,4-bis (1-aziridinecarboxamide), triethylenemelamine, isophthaloylbis-1- (2-methylaziridine), tris-1-aziridinylphosphine oxide, hexamethylene 1,6-bis (1-aziridinecarboxamide), trimethylolpropane tris-β-aziridinylpropionate, tetramethylolmethane, tris-β-aziridinylpropionate, and the like.

Among these crosslinking agents, isocyanate compounds, in particular, xylylene diisocyanate, tolylene diisocyanate or hexamethylene diisocyanate, or adducts obtained by reacting these isocyanate compounds with polyols such as glycerol and trimethylolpropane, and isocyanate compounds A dimer, trimer or the like, or a mixture of these isocyanate compounds is preferably used.

Particularly suitable isocyanate compounds include tolylene diisocyanate, adducts obtained by reacting tolylene diisocyanate with polyols, dimers of tolylene diisocyanate, and trimers of tolylene diisocyanate.

The crosslinking agent (B) is blended at a ratio of 0.01 to 5 parts by weight with respect to 100 parts by weight of the (meth) acrylic resin (A). The blending amount of the crosslinking agent (B) is preferably about 0.1 to 3 parts by weight, more preferably about 0.1 to 1 part by weight with respect to 100 parts by weight of the (meth) acrylic resin (A). The pressure-sensitive adhesive layer constituted by using the pressure-sensitive adhesive composition when the amount of the crosslinking agent (B) relative to 100 parts by weight of the (meth) acrylic resin (A) is 0.01 parts by weight or more, particularly 0.1 parts by weight or more In view of the tendency to improve the durability, the amount of 5 parts by weight or less is preferable because white spots are not noticeable when an optical film with an adhesive is applied to a liquid crystal display device.

[Silane compound (C)]
When the pressure-sensitive adhesive composition of the present invention forms a pressure-sensitive adhesive sheet or an optical film with a pressure-sensitive adhesive, the silane compound (C) represented by the above formula (I) is used to improve the adhesion between the pressure-sensitive adhesive composition and the glass substrate. )including. The silane compound (C) is preferably contained in the (meth) acrylic resin (A) before blending the crosslinking agent.

In the present invention, by containing the silane compound (C) represented by the above formula (I), it is possible to form a pressure-sensitive adhesive layer having excellent adhesion with a glass substrate and having an appropriate adhesive force, When the pressure-sensitive adhesive layer is peeled from the glass substrate, a pressure-sensitive adhesive layer having excellent peelability can be formed by adding water to the interface between the pressure-sensitive adhesive layer and the glass substrate.

In the silane compound (C) represented by the above formula (I), R ₁ represents an alkyl group having 1 to 14 carbon atoms, an aralkyl group, an aryl group, or an alkenyl group. As a specific example, R ₁ represents a methyl group , An ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a pentyl group, and a hexyl group. In the silane compound (C) represented by the above formula (I), R ₂ represents an alkyl group having 1 to 6 carbon atoms, and specific examples include compounds in which R ₂ is a methyl group, an ethyl group, or a propyl group. Is mentioned. Among these, 3-ureidopropyltrialkoxysilane is suitable as the silane compound (C) represented by the above formula (I). In addition, you may contain the silane type compound (C) represented by 2 or more types of formula (I).

As the silane compound contained in the pressure-sensitive adhesive composition of the present invention, the silane compound (C) represented by the formula (I) described above may be contained alone, or the formula (I And a silane compound other than (C) other than the silane compound represented by formula (I) together with the silane compound (C) represented by formula (I). Examples of silane compounds other than the silane compound (C) represented by the formula (I) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, 3-glycidoxypropyltri Methoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltri Methoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyldimethoxymethylsilane, 3-glycidoxypropyl ethoxy Sidimethylsilane and the like, and may be of a silicone oligomer type. When the silicone oligomer is shown in the form of (monomer)-(monomer) copolymer, for example, the following can be mentioned.

3-mercaptopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-mercaptopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-mercaptopropyltriethoxysilane-tetramethoxysilane copolymer, and 3-mercaptopropyltriethoxysilane-tetraethoxy A copolymer containing a mercaptopropyl group, such as a silane copolymer;
Mercaptomethyl groups, such as mercaptomethyltrimethoxysilane-tetramethoxysilane copolymer, mercaptomethyltrimethoxysilane-tetraethoxysilane copolymer, mercaptomethyltriethoxysilane-tetramethoxysilane copolymer, and mercaptomethyltriethoxysilane-tetraethoxysilane copolymer Containing copolymers; 3-methacryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-methacryloyloxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-methacryloyloxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-methacryloyloxy Propyltriethoxysilane-tetraethoxysilane copolymer, 3-methacrylic Royloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-methacryloyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-methacryloyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, and 3-methacryloyloxypropylmethyldiethoxy Copolymers containing methacryloyloxypropyl groups, such as silane-tetraethoxysilane copolymers;
3-acryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-acryloyloxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-acryloyloxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-acryloyloxypropyltriethoxysilane -Tetraethoxysilane copolymer, 3-acryloyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-acryloyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-acryloyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, and 3-acryloyloxypropylmethyldiethoxysilane-tetraethoxysilane Rimmer such as, acryloyloxypropyl group-containing copolymer;
Vinyltrimethoxysilane-tetramethoxysilane copolymer, vinyltrimethoxysilane-tetraethoxysilane copolymer, vinyltriethoxysilane-tetramethoxysilane copolymer, vinyltriethoxysilane-tetraethoxysilane copolymer, vinylmethyldimethoxysilane-tetramethoxysilane copolymer, Vinyl group-containing copolymers such as vinylmethyldimethoxysilane-tetraethoxysilane copolymer, vinylmethyldiethoxysilane-tetramethoxysilane copolymer, and vinylmethyldiethoxysilane-tetraethoxysilane copolymer. Two or more silane compounds other than the silane compound (C) represented by the formula (I) may be used.

Silane compounds are often liquids. The compounding amount of the silane compound (C) represented by the formula (I) in the pressure-sensitive adhesive composition is 0.01 to 10 parts by weight with respect to 100 parts by weight of the solid content of the (meth) acrylic resin (A). Yes, preferably 0.03 to 2 parts by weight, more preferably 0.2 to 1 part by weight. In addition, when containing silane type compounds other than the silane type compound (C) represented by Formula (I), together with the silane type compound (C) represented by Formula (I), (meth) acrylic resin ( The amount is about 0.01 to 10 parts by weight, preferably 0.03 to 2 parts by weight, and more preferably 0.2 to 1 part by weight with respect to 100 parts by weight of the solid content of A). When the amount of the silane compound (C) represented by the formula (I) with respect to 100 parts by weight of the solid content of the (meth) acrylic resin (A) is 0.01 parts by weight or more, particularly 0.03 parts by weight or more, It is preferable because the adhesion and durability between the pressure-sensitive adhesive layer and the glass substrate are improved. Further, it is preferably 0.2 parts by weight or more, since the adhesive force when water is added to the interface between the pressure-sensitive adhesive layer and the glass substrate can be greatly reduced, and the peelability can be further improved. When the content of the silane compound (C) represented by formula (I) and the other silane compound is 10 parts by weight or less, particularly 2 parts by weight or less, or 1 part by weight or less, It is preferable because the silane compound tends to be suppressed from bleeding out from the pressure-sensitive adhesive layer.

[Ionic compounds]
The pressure-sensitive adhesive composition may further contain an ionic compound as an antistatic agent for imparting antistatic properties to the pressure-sensitive adhesive layer. The ionic compound is a compound having an inorganic cation or an organic cation and an inorganic anion or an organic anion. Two or more ionic compounds may be used.

Examples of the inorganic cation include alkali metal ions such as lithium cation [Li ⁺ ], sodium cation [Na ⁺ ], and potassium cation [K ⁺ ], beryllium cation [Be ²⁺ ], and magnesium cation [Mg ²⁺ ]. And alkaline earth metal ions such as calcium cation [Ca ²⁺ ].

Examples of the organic cation include an imidazolium cation, a pyridinium cation, a pyrrolidinium cation, an ammonium cation, a sulfonium cation, and a phosphonium cation.

Among the cation components described above, the organic cation component is preferably used because of its excellent compatibility with the pressure-sensitive adhesive composition. Among organic cation components, pyridinium cation and imidazolium cation are particularly preferably used from the viewpoint that they are difficult to be charged when the release film provided on the pressure-sensitive adhesive layer is peeled off.

Examples of inorganic anions include chloride anions [Cl ⁻ ], bromide anions [Br ⁻ ], iodide anions [I ⁻ ], tetrachloroaluminate anions [AlCl ₄ ⁻ ], heptachlorodialuminate anions [Al ₂ Cl ₇ ⁻ ], tetrafluoroborate anion [BF ₄ ⁻ ], hexafluorophosphate anion [PF ₆ ⁻ ], perchlorate anion [ClO ₄ ⁻ ], nitrate anion [NO ₃ ⁻ ], hexafluoroarsenate anion [AsF _6] ^- ], Hexafluoroantimonate anion [SbF ₆ ⁻ ], hexafluoro niobate anion [NbF ₆ ⁻ ], hexafluoro tantalate anion [TaF ₆ ⁻ ], dicyanamide anion [(CN) ₂ N ⁻ ] and the like. It is done.

Examples of the organic anion include acetate anion [CH ₃ COO ⁻ ], trifluoroacetate anion [CF ₃ COO ⁻ ], methanesulfonate anion [CH ₃ SO ₃ ⁻ ], trifluoromethanesulfonate anion [CF ₃ SO ₃ ⁻ ], p-toluenesulfonate anion [p-CH ₃ C ₆ H ₄ SO ₃ ⁻ ], bis (fluorosulfonyl) imide anion [(FSO ₂ ) ₂ N ⁻ ], bis (trifluoromethanesulfonyl) imide anion [(CF ₃ SO ₂ ) ₂ N ⁻ ], tris (trifluoromethanesulfonyl) methanide anion [(CF ₃ SO ₂ ) ₃ C ⁻ ], dimethyl phosphinate anion [(CH ₃ ) ₂ POO ⁻ ], (poly) hydrofluorofluoride anion [ F (HF) _n ⁻ ] (n is about 1 to 3), thiocyan anion [SC N ^-], perfluorobutane sulfonate anion [C ₄ F ₉ SO ₃ ^-], bis (pentafluoroethane sulfonyl) imide anion _{_{_{[(C 2 F 5 SO 2)}}} 2 N - ], perfluoro butanoate anion [C ₃ F ₇ COO ⁻ ], (trifluoromethanesulfonyl) (trifluoromethanecarbonyl) imide anion [(CF ₃ SO ₂ ) (CF ₃ CO) N ⁻ ], perfluoropropane-1,3-disulfonate anion [ ⁻ O ₃ S (CF ₂ ) ₃ SO ₃ ⁻ ], carbonate anion [CO ₃ ²⁻ ] and the like.

Among the above-mentioned anion components, an anion component containing a fluorine atom is preferably used because it gives an ionic compound having excellent antistatic performance. Specific examples include a bis (fluorosulfonyl) imide anion, a hexafluorophosphate anion, or a bis (trifluoromethanesulfonyl) imide anion.

Specific examples of the ionic compound can be appropriately selected from a combination of the above cation component and anion component. Examples of ionic compounds having an organic cation are listed below according to the structure of the organic cation.

Pyridinium salt:
N-hexylpyridinium hexafluorophosphate,
N-octylpyridinium hexafluorophosphate,
N-octyl-4-methylpyridinium hexafluorophosphate,
N-butyl-4-methylrupyridinium hexafluorophosphate,
Tetrabutylammonium hexafluorophosphate,
N-decylpyridinium bis (fluorosulfonyl) imide,
N-dodecylpyridinium bis (fluorosulfonyl) imide,
N-tetradecylpyridinium bis (fluorosulfonyl) imide,
N-hexadecylpyridinium bis (fluorosulfonyl) imide,
N-dodecyl-4-methylpyridinium bis (fluorosulfonyl) imide,
N-tetradecyl-4-methylpyridinium bis (fluorosulfonyl) imide,
N-hexadecyl-4-methylpyridinium bis (fluorosulfonyl) imide,
N-benzyl-2-methylpyridinium bis (fluorosulfonyl) imide,
N-benzyl-4-methylpyridinium bis (fluorosulfonyl) imide N-hexylpyridinium bis (trifluoromethanesulfonyl) imide,
N-octylpyridinium bis (trifluoromethanesulfonyl) imide,
N-octyl-4-methylpyridinium bis (trifluoromethanesulfonyl) imide,
N-butyl-4-methyllpyridinium bis (trifluoromethanesulfonyl) imide.

Imidazolium salt:
1-ethyl-3-methylimidazolium hexafluorophosphate,
1-ethyl-3-methylimidazolium p-toluenesulfonate,
1-ethyl-3-methylimidazolium bis (fluorosulfonyl) imide 1-ethyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide 1-butyl-3-methylimidazolium methanesulfonate,
1-butyl-3-methylimidazolium bis (fluorosulfonyl) imide.

Pyrrolidinium salt:
N-butyl-N-methylpyrrolidinium hexafluorophosphate,
N-butyl-N-methylpyrrolidinium bis (fluorosulfonyl) imide N-butyl-N-methylpyrrolidinium bis (trifluoromethanesulfonyl) imide.

Quaternary ammonium salt:
Tetrabutylammonium p-toluenesulfonate,
(2-hydroxyethyl) trimethylammonium bis (trifluoromethanesulfonyl) imide,
(2-Hydroxyethyl) trimethylammonium dimethylphosphinate.

Examples of the ionic compound having an inorganic cation include the following.
Lithium bromide,
Lithium iodide,
Lithium tetrafluoroborate,
Lithium hexafluorophosphate,
Lithium thiocyanate,
Lithium perchlorate,
Lithium trifluoromethanesulfonate,
Lithium bis (fluorosulfonyl) imide lithium bis (trifluoromethanesulfonyl) imide,
Lithium bis (pentafluoroethanesulfonyl) imide,
Lithium tris (trifluoromethanesulfonyl) methanide,
Lithium p-toluenesulfonate,
Sodium hexafluorophosphate,
Sodium bis (fluorosulfonyl) imide,
Sodium bis (trifluoromethanesulfonyl) imide,
Sodium p-toluenesulfonate,
Potassium hexafluorophosphate,
Potassium bis (fluorosulfonyl) imide,
Potassium bis (trifluoromethanesulfonyl) imide,
Potassium p-toluenesulfonate.

The ionic compound is preferably a solid at room temperature. Compared with the case of using an ionic compound that is liquid at room temperature, the antistatic performance can be maintained for a long time. From the viewpoint of such antistatic long-term stability, the ionic compound preferably has a melting point of 30 ° C. or higher, more preferably 35 ° C. or higher. On the other hand, if the melting point is too high, the compatibility with the (meth) acrylic resin (A) is deteriorated, so the melting point is preferably 90 ° C. or less, more preferably 70 ° C. or less, and even more preferably less than 50 ° C. It is.

The content of the ionic compound in the pressure-sensitive adhesive composition is preferably 0.2 to 8 parts by weight, more preferably 0.2 to 5 parts by weight with respect to 100 parts by weight of the (meth) acrylic resin (A). Part, more preferably 0.3 to 5 parts by weight, and particularly preferably 0.5 to 3 parts by weight. The content of the ionic compound being 0.2 parts by weight or more is advantageous for improving the antistatic performance, and the content of 8 parts by weight or less is advantageous for maintaining the durability of the pressure-sensitive adhesive layer.

[Other ingredients]
The pressure-sensitive adhesive composition is an additive such as a crosslinking catalyst, a weather stabilizer, a tackifier, a plasticizer, a softener, a dye, a pigment, an inorganic filler, a light scattering fine particle, and a resin other than the (meth) acrylic resin (A). Can be contained. If a cross-linking catalyst is blended with the cross-linking agent in the pressure-sensitive adhesive composition, the pressure-sensitive adhesive sheet can be prepared by a short time curing, and the resulting optical film with the pressure-sensitive adhesive floats between the optical film and the pressure-sensitive adhesive sheet. It is possible to suppress occurrence of peeling or foaming in the pressure-sensitive adhesive sheet. In addition, it is also useful to blend an ultraviolet curable compound into the pressure-sensitive adhesive composition, form an pressure-sensitive adhesive layer, and then cure by irradiating with ultraviolet rays to form a harder pressure-sensitive adhesive layer. Examples of the crosslinking catalyst include amine compounds such as hexamethylenediamine, ethylenediamine, polyethyleneimine, hexamethylenetetramine, diethylenetriamine, triethylenetetramine, isophoronediamine, trimethylenediamine, polyamino resin, and melamine resin.

[Preparation of pressure-sensitive adhesive composition]
Each component demonstrated above is mixed in the state melt | dissolved in the solvent, and is set as an adhesive composition. Here, examples of the solvent include aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; aliphatic alcohols such as propyl alcohol and isopropyl alcohol; acetone, methyl ethyl ketone, and methyl isobutyl ketone. Ketones such as can be used. This pressure-sensitive adhesive composition exhibits good performance, but it preferably does not contain an amino group in order to avoid strong adhesion when it comes into contact with a specific release film. In particular, it is preferable not to have a tertiary amino group.

The pressure-sensitive adhesive composition dissolved in the above solvent is applied onto a suitable substrate and dried to form a pressure-sensitive adhesive sheet. The substrate used here is generally a plastic film, and a typical example thereof is a release film that has been subjected to a release treatment. The release film is, for example, a film on which a pressure-sensitive adhesive sheet of a film made of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, and polyarylate is formed and subjected to a release treatment such as a silicone treatment. be able to.

[Adhesive sheet]
As described above, the pressure-sensitive adhesive sheet of the present invention is formed into a sheet shape from the pressure-sensitive adhesive composition described above. In the present specification, the “pressure-sensitive adhesive sheet” in the laminate may be referred to as “pressure-sensitive adhesive layer”. The pressure-sensitive adhesive sheet of the present invention is preferably used after curing for a certain period of time, preferably 7 days or more, and allowing the crosslinking reaction to proceed. The pressure-sensitive adhesive sheet of the present invention preferably has a gel fraction of 65 to 85% after it is coated into a sheet and left at room temperature for 7 days. By having such a gel fraction, the pressure-sensitive adhesive sheet exhibits excellent durability.

Here, the gel fraction is a value measured according to the following (1) to (4).
(1) An adhesive sheet having an area of about 8 cm × about 8 cm and a metal mesh made of SUS304 (about 10 cm × about 10 cm) (with a weight of Wm) are bonded.
(2) Weigh the bonded product obtained in (1) above, weigh it Ws, then fold it 4 times so as to wrap the adhesive sheet, weigh it with a stapler (stapler), weigh it, Let the weight be Wb.
(3) The mesh stapled in (2) above is placed in a glass container, and 60 mL of ethyl acetate is added and immersed, and then the glass container is stored at room temperature for 3 days.
(4) The mesh is taken out from the glass container, dried at 120 ° C. for 24 hours, weighed, and its weight is defined as Wa.
Gel fraction (% by weight) = [{Wa− (Wb−Ws) −Wm} / (Ws−Wm)] × 100
Calculate the gel fraction based on

In addition, the gel fraction after leaving for 7 days can be adjusted with the kind of (meth) acrylic resin (A) which is an active ingredient of the adhesive composition which forms it, and the quantity of a crosslinking agent, for example. Specifically, the amount of the monomer having a polar functional group including the monomer (A-2) and the monomer (A-3) in the (meth) acrylic resin (A) is increased, or If the amount of the crosslinking agent (B) in the pressure-sensitive adhesive composition is increased, the gel fraction is increased. Therefore, the gel fraction may be adjusted by adjusting these amounts.

The adhesive strength of the adhesive sheet to glass is preferably 1.0 to 8.0 N / 25 mm. When it is 1.0 N / 25 mm, the adhesive force is too low, and it becomes easy to peel between the glass substrate and the adhesive sheet. If it exceeds 8.0 N / 25 mm, the followability of the pressure-sensitive adhesive sheet with respect to the dimensional change of the optical film may be lowered, and the durability may be lowered. The adhesive strength to glass of the pressure-sensitive adhesive sheet can be controlled by adjusting the elasticity of the base polymer of the pressure-sensitive adhesive composition or by adjusting the blending amount of an additive (for example, a silane compound).

It is preferable that the pressure-sensitive adhesive strength of the pressure-sensitive adhesive sheet is greatly reduced when water is added to the interface between the pressure-sensitive adhesive sheet and the glass substrate. When the adhesive strength of the pressure-sensitive adhesive sheet to the glass substrate when water is not added is P ₁ , and the adhesive strength of the pressure-sensitive adhesive sheet to the glass substrate when water is added is P ₂ , the following formula:
Decrease rate of adhesive strength when water added (%) = (P ₁ −P ₂ ) / P ₁ × 100
The greater the rate of decrease in adhesive strength when water is calculated based on the above, the greater the peelability can be improved by reducing the adhesive strength simply by adding water at the time of peeling, resulting in superior reworkability .

[Optical film with adhesive]
The optical film with pressure-sensitive adhesive of the present invention is obtained by bonding a pressure-sensitive adhesive sheet formed from the above pressure-sensitive adhesive composition to at least one surface of an optical film. The optical film used for the optical film with an adhesive is a film having optical properties, and examples thereof include a polarizing plate and a retardation film.

A polarizing plate is an optical film having a function of emitting polarized light with respect to incident light such as natural light. The polarizing plate absorbs linearly polarized light having a vibrating surface in a certain direction and reflects linearly polarized light having a vibrating surface in a certain direction, and reflects linearly polarized light having a vibrating surface in a certain direction. There are a polarizing separation plate having a property of transmitting linearly polarized light having a vibration plane orthogonal to the polarizing plate, an elliptically polarizing plate in which a polarizing plate and a retardation film described later are laminated. As a suitable specific example of a polarizing film that expresses the function of a polarizing plate, particularly a linear polarizing plate (sometimes called a polarizer), two colors such as iodine and a dichroic dye are applied to a uniaxially stretched polyvinyl alcohol resin film. The thing which the adsorptive orientation of the property pigment is mentioned.

The retardation film is an optical film exhibiting optical anisotropy, for example, polyvinyl alcohol, polycarbonate, polyester, polyarylate, polyimide, polyolefin, cyclic polyolefin, polystyrene, polysulfone, polyethersulfone, polyvinylidene fluoride. / Stretched film obtained by stretching a polymer film composed of polymethyl methacrylate, liquid crystal polyester, acetyl cellulose, saponified ethylene-vinyl acetate copolymer, polyvinyl chloride, etc. by about 1.01 to 6 times. It is done. Among them, a polymer film obtained by uniaxially or biaxially stretching a polycarbonate film or a cyclic polyolefin film is preferable. Although there exist what is called a uniaxial phase difference film, a wide viewing angle phase difference film, a low photoelasticity phase difference film, etc., it is applicable to all.

Also, a film that exhibits optical anisotropy by applying and orienting a liquid crystalline compound and a film that exhibits optical anisotropy by applying an inorganic layered compound can be used as the retardation film. Such a retardation film is a so-called temperature-compensated retardation film, and a rod-like liquid crystal sold under the trade name “LC film” from JX Nippon Mining & Energy Co., Ltd. is twisted to align. A film with a tilted orientation of a rod-like liquid crystal sold under the trade name “NH film” by JX Nippon Mining & Energy Co., Ltd., and a trade name “WV film” by Fuji Film Co., Ltd. A film with a disc-shaped liquid crystal tilt-aligned, a fully biaxially oriented film sold under the trade name “VAC film” by Sumitomo Chemical Co., Ltd., and a “new VAC film” product from Sumitomo Chemical Co., Ltd. There are biaxially oriented films sold by name.

Furthermore, those obtained by attaching a protective film to these optical films can also be used as optical films. As the protective film, a transparent resin film is used, and as the transparent resin, for example, an acetyl cellulose resin typified by triacetyl cellulose or diacetyl cellulose, a methacrylic resin typified by polymethyl methacrylate, a polyester resin, or a polyolefin Resin, polycarbonate resin, polyether ether ketone resin, polysulfone resin and the like. The resin constituting the protective film may contain an ultraviolet absorber such as a salicylic acid ester compound, a benzophenone compound, a benzotriazole compound, a triazine compound, a cyanoacrylate compound, and a nickel complex compound. As the protective film, an acetyl cellulose resin film such as a triacetyl cellulose film is preferably used.

Among the optical films described above, the linear polarizing plate is often used in a state in which a protective film is attached to one or both sides of a polarizing film constituting the polarizing film, for example, a polarizing film made of a polyvinyl alcohol-based resin. . Moreover, although the above-mentioned elliptically polarizing plate is a laminate of a linearly polarizing plate and a retardation film, the linearly polarizing plate is often in a state where a protective film is attached to one side or both sides of the polarizing film. . When bonding the adhesive sheet by this invention to such an elliptically polarizing plate, it is normally bonded by the phase difference film side.

For the optical film with adhesive, it is preferable that a release film having been subjected to a release treatment as described above is attached to the surface of the adhesive layer to protect the surface of the adhesive layer until use. An optical film with an adhesive provided with a release film in this way is formed, for example, by applying the above-mentioned adhesive composition to the release treatment surface of the release film to form an adhesive sheet, A method of laminating on an optical film, a method of applying a pressure-sensitive adhesive composition on an optical film to form a pressure-sensitive adhesive sheet, attaching a release film to the surface of the pressure-sensitive adhesive to protect it, and making an optical film with a pressure-sensitive adhesive Can be manufactured.

The thickness of the pressure-sensitive adhesive layer formed on the optical film is not particularly limited, but is usually 30 μm or less, preferably 10 μm or more, and more preferably 15 to 25 μm. When the thickness of the pressure-sensitive adhesive layer is 30 μm or less, the adhesiveness under high temperature and high humidity is improved, and the possibility of floating or peeling between the glass substrate and the pressure-sensitive adhesive layer tends to be reduced. In addition, it is preferable because reworkability tends to be improved, and when the thickness is 10 μm or more, the adhesive layer follows the change in dimension even if the dimension of the optical film bonded thereto changes. Therefore, it is preferable because there is no difference between the brightness of the peripheral edge of the liquid crystal cell and the brightness of the central portion, and white spots and color unevenness tend to be suppressed.

The optical film with pressure-sensitive adhesive of the present invention is bonded to a glass substrate to form an optical laminate, and when there is some trouble and the optical film is peeled off from the glass substrate, the adhesive film and the glass substrate at the interface. By adding water, the adhesive strength of the pressure-sensitive adhesive layer is greatly reduced and excellent peelability is exhibited. Therefore, the pressure-sensitive adhesive layer is peeled off along with the optical film, and almost no fogging or adhesive residue is generated on the surface of the glass substrate that is in contact with the pressure-sensitive adhesive layer. It is easy to reapply the optical film. In addition, when re-adhering the optical film with the adhesive on the glass substrate after peeling, if the water added at the time of peeling adheres on the glass substrate, it is necessary to wipe off the water before re-sticking. It is preferable because of its good properties. Similarly, when the adhesive-attached optical film after peeling is bonded to a glass substrate, if water is attached to the adhesive layer, it is possible to wipe off the water and re-apply it. Therefore, it is preferable.

[Optical laminate]
The optical film with pressure-sensitive adhesive of the present invention can be made into an optical laminate by bonding the pressure-sensitive adhesive layer side to a glass substrate. In order to laminate an optical film with an adhesive on a glass substrate to form an optical laminate, for example, the release film is peeled off from the optical film with an adhesive obtained as described above, and the exposed adhesive layer surface is the surface of the glass substrate. You just have to stick together. As a glass substrate, the glass substrate of a liquid crystal cell, the glass for glare-proof, the glass for sunglasses etc. can be mentioned, for example. Among them, an optical film with an adhesive (upper polarizing plate) is laminated on the glass substrate on the front side (viewing side) of the liquid crystal cell, and another optical film with adhesive (lower polarizing plate) on the glass substrate on the back side of the liquid crystal cell. ) Is preferable because it can be used as a panel (liquid crystal panel) for a liquid crystal display device. Examples of the material of the glass substrate include soda lime glass, low alkali glass, non-alkali glass, and the like, and non-alkali glass is suitably used for the liquid crystal cell.

Examples of some suitable layer configurations of the optical laminate according to the present invention are shown in cross-sectional schematic views in FIG. In the example shown in FIG. 1 (A), a polarizing film 5 is configured by sticking a protective film 3 having a surface treatment layer 2 on one surface of a polarizing film 1 on the surface opposite to the surface treatment layer 2. ing.
In this example, the polarizing plate 5 is also the optical film 10 referred to in the present invention. An adhesive layer 20 is provided on the surface of the polarizing film 1 opposite to the protective film 3 to form an optical film 25 with an adhesive. And the surface on the opposite side to the polarizing plate 5 of the adhesive layer 20 is bonded to the liquid crystal cell 30 which is a glass substrate, and the optical laminated body 40 is comprised.

In the example shown in FIG. 1B, the first protective film 3 having the surface treatment layer 2 is attached to one surface of the polarizing film 1 on the surface opposite to the surface treatment layer 2. On the other surface, a second protective film 4 is stuck to form a polarizing plate 5. Also in this example, the polarizing plate 5 is simultaneously the optical film 10 referred to in the present invention. An adhesive layer 20 is provided on the outer side of the second protective film 4 constituting the polarizing plate 5 to form an optical film 25 with an adhesive. And the surface on the opposite side to the polarizing plate 5 of the adhesive layer 20 is bonded to the liquid crystal cell 30 which is a glass substrate, and the optical laminated body 40 is comprised.

In the example shown in FIG. 1 (C), a polarizing film 5 is formed by sticking a protective film 3 having a surface treatment layer 2 on one side of a polarizing film 1 on the surface opposite to the surface treatment layer 2. Yes. On the surface of the polarizing film 1 opposite to the protective film 3, a retardation film 7 is stuck via an interlayer adhesive 8 to constitute an optical film 10. An adhesive layer 20 is provided on the outer side of the retardation film 7 constituting the optical film 10 to constitute an optical film 25 with an adhesive.
And the surface on the opposite side to the optical film 10 of the adhesive layer 20 is bonded to the liquid crystal cell 30 which is a glass substrate, and the optical laminated body 40 is comprised.

In the example shown in FIG. 1 (D), the first protective film 3 having the surface treatment layer 2 is attached to one surface of the polarizing film 1 on the surface opposite to the surface treatment layer 2, and the polarizing film A polarizing plate 5 is configured by sticking a second protective film 4 to the other surface of 1. On the outer side of the second protective film 4 constituting the polarizing plate 5, a retardation film 7 is stuck via an interlayer adhesive 8 to constitute an optical film 10. An adhesive layer 20 is provided on the outer side of the retardation film 7 constituting the optical film 10 to constitute an optical film 25 with an adhesive. And the surface on the opposite side to the optical film 10 of the adhesive layer 20 is bonded to the liquid crystal cell 30 which is a glass substrate, and the optical laminated body 40 is comprised.

In these examples, the first protective film 3 and the second protective film 4 are generally composed of a triacetyl cellulose film, but may be composed of the various transparent resin films described above. it can. The surface treatment layer formed on the surface of the first protective film 3 can be a hard coat layer, an antiglare layer, an antireflection layer, an antistatic layer, or the like.
Of these, a plurality of layers may be provided.

As shown in FIGS. 1C and 1D, when the retardation film 7 is laminated on the polarizing plate 5, a suitable example of the retardation film 7 is a medium-to-small liquid crystal display device. And a quarter-wave plate. In this case, it is general that the absorption axis of the polarizing plate 5 and the slow axis of the retardation film 7 which is a quarter wavelength plate are arranged so as to intersect at about 45 degrees. Depending on the characteristics, the angle may be shifted from 45 degrees to some extent. On the other hand, in the case of a large liquid crystal display device such as a television, a retardation film having various retardation values in accordance with the characteristics of the liquid crystal cell 30 is used for the purpose of phase difference compensation and viewing angle compensation of the liquid crystal cell 30. .
In this case, the polarizing plate 5 and the retardation film 7 are generally arranged so that the absorption axis and the slow axis of the retardation film 7 are substantially orthogonal or substantially parallel. When the retardation film 7 is composed of a quarter wavelength plate, a uniaxial or biaxial stretched film is preferably used. When the retardation film 7 is provided for the purpose of retardation compensation or viewing angle compensation of the liquid crystal cell 30, in addition to the uniaxial or biaxially stretched film, it is also oriented in the thickness direction in addition to the uniaxial or biaxially stretched film. What is called an optical compensation film, such as a film or a film obtained by coating and fixing a retardation-expressing substance such as liquid crystal on a support film, can also be used as the retardation film 7.

Similarly, when the polarizing plate 5 and the retardation film 7 are bonded via the interlayer adhesive 8 as in the example shown in FIGS. 1C and 1D, the interlayer adhesive 8 includes A typical acrylic pressure-sensitive adhesive is usually used, but it is of course possible to use a pressure-sensitive adhesive sheet as defined herein. In the case where the absorption axis of the polarizing plate 5 and the slow axis of the retardation film 7 are arranged so as to be substantially orthogonal or substantially parallel like the large liquid crystal display device described above, In applications where the phase difference film 7 can be roll-to-roll-bonded and re-peelability between the two is not required, the interlayer adhesive 8 shown in (C) and (D) of FIG. It is also possible to use an adhesive that can be firmly bonded once bonded and cannot be peeled off. As such an adhesive, for example, an aqueous adhesive that is composed of an aqueous solution or an aqueous dispersion and exhibits adhesive strength by evaporating water as a solvent, ultraviolet curing that is cured by ultraviolet irradiation and exhibits adhesive strength. Examples thereof include a mold adhesive.

1 (C) and (D) shown in FIG. 1 can also be distributed by themselves, in which the pressure-sensitive adhesive layer 20 is formed on the retardation film 7. Can be a film. An optical film with an adhesive with an adhesive layer formed on a retardation film can be bonded to a liquid crystal cell that is a glass substrate to form an optical laminate, and a polarizing plate is provided on the retardation film side. It can also paste and can be set as another optical film with an adhesive.

FIG. 1 shows an example in which the optical film 25 with an adhesive is arranged on the viewing side of the liquid crystal cell 30, but the optical film with an adhesive according to the present invention is the back side of the liquid crystal cell, that is, the back. It can also be placed on the light side. When the optical film with pressure-sensitive adhesive of the present invention is disposed on the back side of the liquid crystal cell, a protective film having no surface treatment layer is employed instead of the protective film 3 having the surface treatment layer 2 shown in FIG. Others can be configured similarly to (A) to (D) of FIG. In this case, various optical films known to be disposed on the back side of the liquid crystal cell, such as a brightness enhancement film, a light collecting film, and a diffusion film, may be provided outside the protective film constituting the polarizing plate. Is possible.

As described above, the optical layered body of the present invention can be suitably used for a liquid crystal display device. The liquid crystal display device formed from the optical laminate of the present invention includes, for example, a notebook type, a desktop type, a personal computer liquid crystal display including a PDA (Personal Digital Assistant), a television, an in-vehicle display, an electronic dictionary, and a digital camera. It can be used for digital video cameras, electronic desk calculators, watches, etc.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In the examples, “%” and “part” representing the content or amount used are based on weight unless otherwise specified. First, polymerization examples A to C in which the (meth) acrylic resin (A) as the main component of the pressure-sensitive adhesive composition was produced are shown.

<Polymerization examples A to C of (meth) acrylic resin (A)>
In a reaction vessel equipped with a cooling tube, a nitrogen introducing tube, a thermometer and a stirrer, 81.8 parts of ethyl acetate, butyl acrylate (hereinafter also referred to as “BA”) as a monomer (A-1), methyl acrylate (Hereinafter also referred to as “MA”), 2- (2-phenoxyethoxy) ethyl acrylate (hereinafter also referred to as “PEA2”), and 2-hydroxyethyl acrylate (hereinafter referred to as “PEA2”) as monomer (A-2). (Also referred to as “HEA”), 2-carboxyethyl acrylate (hereinafter also referred to as “CEA”) as monomer (A-3), monomers (A-1), (A-2) and ( Acrylic acid (hereinafter also referred to as “AA”) is charged in the amount shown in Table 1 as a monomer other than A-3), and the internal temperature is controlled by replacing the air in the apparatus with nitrogen gas so as not to contain oxygen. Raised to 55 ° C. Thereafter, a total amount of a solution prepared by dissolving 0.14 part of azobisisobutyronitrile (polymerization initiator) in 10 parts of ethyl acetate was added. One hour after the addition of the initiator, this temperature is maintained, and then, while maintaining the internal temperature at 54 to 56 ° C., ethyl acetate is continuously added into the reaction vessel at an addition rate of 17.3 parts / hr. ) When the concentration of the acrylic resin reached 35%, the addition of ethyl acetate was stopped, and the temperature was kept at this temperature until 12 hours passed from the start of the addition of ethyl acetate. Finally, ethyl acetate was added to adjust the concentration of the (meth) acrylic resin to 20% to prepare an ethyl acetate solution of the (meth) acrylic resin.

In the above, as the 2-carboxyethyl acrylate (CEA), the trade name “β-CEA” sold by Daicel Cytec Co., Ltd. was used. Its chemical composition is
CH ₂ = CH (COOCH ₂ CH ₂ ) _n COOH (n = average 1)
Specifically, 2-carboxyethyl acrylate (that is, acrylic acid dimer) 40%, acrylic acid trimer or higher oligomer 40%, and acrylic acid 20%.

Next, Examples and Comparative Examples in which pressure-sensitive adhesives were prepared using the (meth) acrylic resins produced in Polymerization Examples A to C and applied to optical films are shown. In each Example and Comparative Example, those shown in Table 2 were used as the crosslinking agent (B) and the silane compound. The crosslinking agent (B) and silane compound shown in Table 2 are shown below. The first names listed are all product names.

<Crosslinking agent (B)>
Coronate L: Trimethylolpropane adduct of tolylene diisocyanate in ethyl acetate solution (solid content: 75%), obtained from Nippon Polyurethane Co., Ltd.

<Silane compound (C) represented by formula (I)>
KBM-585: 3-ureidopropyltrialkoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.

<Silane compounds other than the silane compound (C) represented by the formula (I)>
KBM-403: 3-glycidoxypropyltrimethoxysilane, liquid, manufactured by Shin-Etsu Chemical Co., Ltd.
KBM-4803: Glycidoxyoctyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.
A100: acetoacetylpropyltrimethoxysilane, manufactured by Soken Chemical Co., Ltd.
KBM-573: N-phenyl-3-aminopropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.

<Ionic compounds>
N-octyl-4-methylpyridinium hexafluorophosphate (melting point 44 ° C.).

[Examples 1 to 4 and Comparative Examples 1 to 6]
(A) Production of pressure-sensitive adhesive compositions of Examples 1 to 4 and Comparative Examples 1 to 6 Solid content of 20% ethyl acetate solution of (meth) acrylic resin obtained in any of Polymerization Examples A to C shown in Table 2 To 100 parts by weight, 0.5 parts by weight of the cross-linking agent and the above silane compound are mixed in the amounts shown in Table 2, and ethyl acetate is added so that the solids concentration is 13%. Thus, pressure-sensitive adhesive compositions of Examples 1 to 4 and Comparative Examples 1 to 6 were prepared.

(B) Production of pressure-sensitive adhesive sheet Each pressure-sensitive adhesive composition prepared in (a) above was subjected to a release treatment on a polyethylene terephthalate film [trade name “SP-PLR382050”, obtained from Lintec Corporation, separator Was applied using an applicator so that the thickness after drying was 20 μm, and dried at 100 ° C. for 1 minute to prepare an adhesive sheet.

(C) Measurement of gel fraction of pressure-sensitive adhesive sheet After the pressure-sensitive adhesive sheet prepared in (b) was allowed to stand at room temperature for 7 days, the gel fraction was measured by the method described above. Table 2 shows the measurement results.

(D) Preparation of polarizing plate with pressure-sensitive adhesive The polarizing plate having a three-layer structure in which both surfaces of a polarizing film in which iodine is adsorbed and oriented on polyvinyl alcohol is sandwiched between protective films made of triacetyl cellulose are combined with the above (b The surface of the pressure-sensitive adhesive sheet produced in step (1) (the surface of the pressure-sensitive adhesive layer) is pasted with a laminator and then cured for 7 days at a temperature of 23 ° C. and a relative humidity of 65%. Produced.

(E) Production and Evaluation of Optical Laminate After separating the separator from the pressure-sensitive adhesive polarizing plate produced in (d) above, the pressure-sensitive adhesive layer surface was a glass substrate for liquid crystal cells [trade name “EAGLE XG”, from Corning Inc. It was pasted on both sides of [Acquisition] so as to be crossed Nicol, and an optical laminate was produced. When this optical laminated body was subjected to a heat resistance test for 300 hours under dry conditions at a temperature of 80 ° C. (indicated as “heat resistance” in Table 2), the moisture heat resistance test was stored for 300 hours at a temperature of 60 ° C. and a relative humidity of 90%. (In Table 2, “Wet heat resistance”) and the process of lowering the temperature from −70 ° C. to −40 ° C. and then raising the temperature to 70 ° C. is defined as one cycle (1 hour). When the heat shock resistance test was repeated for 100 cycles (indicated as “HS resistance” in Table 2), the optical laminate after the test was visually observed. The results were classified according to the following criteria and summarized in Table 2.

<Evaluation criteria for heat resistance test, heat and humidity resistance test and heat shock resistance test>
A: No change in appearance such as floating, peeling, foaming, etc.
B: Almost no change in appearance such as floating, peeling, foaming, etc.
C: Appearance changes such as floating, peeling and foaming are slightly noticeable.
D: Appearance changes such as floating, peeling and foaming are remarkably recognized.

(F) Evaluation of adhesive strength to glass of optical film with pressure-sensitive adhesive The polarizing plate with pressure-sensitive adhesive prepared in (d) above was cut into a size of 25 mm × 200 mm so that the absorption axis of the polarizing film was parallel to the long side. A sample for evaluation was used. After peeling the separator from the sample for evaluation, the pressure-sensitive adhesive layer surface was bonded to an alkali-free glass plate (“Eagle-XG” manufactured by Corning), and then in an autoclave at a temperature of 50 ° C. and a pressure of 5 MPa. The pressure treatment was performed for 20 minutes, and the mixture was then left for 1 day in an atmosphere at a temperature of 23 ° C. and a relative humidity of 60%. After that, using an autograph (“AGS-50NX” manufactured by Shimadzu Corporation) in an environment at a temperature of 23 ° C. and a relative humidity of 60%, one end in the length direction of the sample for evaluation was grasped, and the peeling rate was 300 mm / min. in performs the 180 ° peel test to give-glass adhesion (water added No) P ₁ by measuring the stress at peeling. Moreover, about the sample for evaluation bonded to the alkali-free glass plate adjusted similarly, 1 ml of water is dripped at the interface of a non-alkali glass plate and an adhesive layer surface, and the length direction end of the sample for evaluation is grasped and peeled off. It performs 180 ° peel test at a rate of 300 mm / min, to give-glass adhesion (water added Yes) P ₂ by measuring the stress at peeling. Further, by using the P ₁ and P _2, it was calculated adhesion rate of decrease upon addition of water in the manner previously described. The results are shown in Table 2.

As shown in Table 2, with respect to the pressure-sensitive adhesive composition using the (meth) acrylic resin obtained in Polymerization Example A, Example 1 has a decrease rate of the adhesive strength as compared with Comparative Examples 1, 4, 5, and 6. It was expensive.
Regarding the pressure-sensitive adhesive composition using the (meth) acrylic resin obtained in Polymerization Example B, Examples 2 and 3 had a higher adhesive force reduction rate than Comparative Example 2. Regarding the pressure-sensitive adhesive composition using the (meth) acrylic resin obtained in Polymerization Example C, Example 4 had a higher adhesive force reduction rate than Comparative Example 3.

1 polarizing film, 2 surface treatment layer, 3 (first) protective film, 4 second protective film, 5 polarizing plate, 7 retardation film, 8 interlayer adhesive, 10 optical film, 20 liquid crystal cell (glass substrate) Adhesive layer (adhesive sheet) to be bonded to 25, 25 optical film with adhesive, 30 liquid crystal cell (glass substrate), 40 optical laminate.

Claims

(Meth) acrylic resin, crosslinking agent, and the following formula (I)

(In the above formula (I), R 1 represents an alkyl group having 1 to 14 carbon atoms or an aralkyl group, aryl group or alkenyl group; R 2 represents an alkyl group having 1 to 6 carbon atoms)
A pressure-sensitive adhesive composition containing a silane compound represented by:
The pressure-sensitive adhesive composition according to claim 1, wherein the silane compound is contained in an amount of 0.03 to 10 parts by weight with respect to 100 parts by weight of the (meth) acrylic resin.
The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the silane compound is 3-ureidopropyltrialkoxysilane.
The pressure-sensitive adhesive composition according to any one of claims 1 to 3, wherein the crosslinking agent is an isocyanate crosslinking agent.
A pressure-sensitive adhesive sheet formed into a sheet shape using the pressure-sensitive adhesive composition according to any one of claims 1 to 4.
The pressure-sensitive adhesive sheet according to claim 5, which is formed on a plastic film.
The pressure-sensitive adhesive sheet according to claim 6, wherein the plastic film is a release film subjected to a release treatment.
An optical film with a pressure-sensitive adhesive comprising an optical film and the pressure-sensitive adhesive sheet according to any one of claims 5 to 7 bonded to the optical film.
The optical film with an adhesive according to claim 8, wherein the optical film is a polarizing plate or a retardation film.
An optical laminate in which the optical film with an adhesive according to claim 8 or 9 is bonded to a glass substrate on the adhesive sheet side.